This invention relates to treated alumina.
Supported chromium oxide catalysts have long been used to prepare olefin polymers in hydrocarbon solution or slurry to give products having excellent characteristics from many standpoints. A number of supports have long been broadly disclosed in the art for chromium oxide catalysts including silica, alumina, thoria, zirconia, silica alumina, and other refractory materials. However, as a practical matter only predominately silica supports have achieved substantial commercial success. Alumina which is almost always included in the prior art in the list of suitable supports, while operable, invariably causes productivity to be extremely low. The preferred prior art support, silica, also suffers from disadvantages among which is the inability to produce ultra high molecular weight polymer using hexavalent chromium.